1. Limited time only! Sign up for a free 30min personal tutor trial with Chegg Tutors
    Dismiss Notice
Dismiss Notice
Join Physics Forums Today!
The friendliest, high quality science and math community on the planet! Everyone who loves science is here!

Fundamental frequency of a wire wheel spoke

  1. Dec 16, 2016 #1
    1. The problem statement, all variables and given/known data
    The spoke of a wire wheel is 9.5 cm long, 3.5 mm in diameter, and under tension of 2100 N. The wire is made of steel of density 7860 kg/m3. When struck with a metal tool at its center, the spoke rings at its fundamental frequency. What is that frequency?

    2. Relevant equations
    λn.fn=v and velocity:v=sqrt(T/μ) , lemda λn=2L/n and L= length of string
    fn=n/2L . sqrt(T/μ)
    fundamental≡ the first mode ⇒ n=1
    μ is the linear mass and must be in kg/m so we must multiply our density by the area which is π.r^2

    3. The attempt at a solution
    μ=7860*π*(3.5*10^-3)^2=0.302 kg/m
    f=1/(2*9.5*10^-2) . sqrt(2100/0.302)
    f= 438.8 Hz
    but the answer is incorrect why??
     
  2. jcsd
  3. Dec 16, 2016 #2

    gneill

    User Avatar

    Staff: Mentor

    I've changed your thread title to more accurately describe the particular problem. Please choose thread titles that are not too general.

    Were you given the radius of the spoke?
     
  4. Dec 16, 2016 #3
    Ah okay. Thanks very much. I used the diameter as a radius wrongly. :)
    Now it will be 877Hz which is the correct answer
     
Know someone interested in this topic? Share this thread via Reddit, Google+, Twitter, or Facebook

Have something to add?
Draft saved Draft deleted



Similar Discussions: Fundamental frequency of a wire wheel spoke
  1. Wheel and spoke (Replies: 1)

Loading...